1. Field of the Invention
The present invention relates to a field emission display (i.e., “FED”) device, and more particularly, to a sealing structure of a FED device and a method of manufacturing the same.
2. Description of the Related Art
In general, a field emission display (i.e., a “FED”) device is one of flat panel display devices, and formed of a tip-shaped or wedge-shaped cathode and an anode on which a fluorescent substance is coated. When electrons emitted from a predetermined portion of the cathode collide with the fluorescent substance, the fluorescent substance illuminates to visually display desired patterns, characters, or signs. The FED device can display high resolution and high luminance color patterns while consuming minimum electrical power.
Such a FED device forms a micro-tip shaped cathode in order to focus an electric field, forms a gate for inducing the electric field, and forms an anode on which a fluorescent substance is coated. Electrons are emitted from a plurality of micro-tips, and the electrons collide with the fluorescent substance of the anode having a transparent conductive film; thus the fluorescent substance is stimulated and the outermost electrons of the fluorescent substance are excited and transited. Then, the light generated by the excitement and transition is used to visually display desired images. Studies about such a FED device have been performed for a long time.
A substrate assembly for a FED device is manufactured during a packaging process, in which an upper substrate and a lower substrate having an anode and a cathode, respectively, are aligned and heated in a firing furnace at a temperature of 400° C.
In such a packaging process described above, however, carbon nano-tubes are easily oxidized in high temperature process due to the oxygen remaining in the firing furnace. In fact, during the packaging process, a large number of the carbon nano-tubes are oxidized, and the emission characteristic of carbon nano-tubes seriously deteriorates. In order to solve such problems, oxygen is completely removed from the firing furnace, and the baking process is performed after injecting an inert gas, such as nitrogen, into the firing furnace.